Thought this was interesting, while fooling around last night with a little overclocking I borrowed a couple sticks from my X79 rig to run some benchmarks on P67. I left the rig to fold overnight with only the two remaining sticks, and woke up this morning to a significant drop in PPD.

So overnight the rig was running in dual channel, 2X4GB of the same 2133 c9 ram, memory usage was under 6GB in total so it wasn't maxed out.

TFP rose to 61 mins, PPD sunk to 95,000

This was a bigger hit than I would have thought going from dual to quad channel, maybe there's something else going on that I'm missing, but thought I'd share.

Dead Things

January 25, 2012 01:07 PM

Quote:

Originally Posted by G777
(Post 594578)

This was a bigger hit than I would have thought going from dual to quad channel, maybe there's something else going on that I'm missing, but thought I'd share.

We saw something similar with the 2P and 4P G34 rigs insomuch as there was a considerable amount of performance to be gained from higher frequency/lower latency RAM in quad-channel. It's interesting because that was essentially the first platform to witness a gain in FAH performance from RAM. By comparison, LGA1366 provided no discernible difference in switching between tri-channel or dual-channel.

Having said that, I share your surprise. I figured part of the reason why memory bandwidth made as much of a difference on G34 is because each processing thread needs its own address space, so a large MP system would depend more heavily on RAM performance. Your findings, though, would suggest it has more to do with the quad-channel bandwidth itself being particularly agreeable to FAH. This is indeed interesting. Thanks for sharing!

Tim_H

January 25, 2012 01:11 PM

I know that it's an issue with a AMD G34 setup, regardless of the number of processors in it so it makes sense I guess.